Sediment characteristics of a thermokarst lagoon in the northeastern Siberian Arctic (Ivashkina Lagoon, Bykovsky Peninsu
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ORIGINAL ARTICLE
Sediment characteristics of a thermokarst lagoon in the northeastern Siberian Arctic (Ivashkina Lagoon, Bykovsky Peninsula) Lutz Schirrmeister1 · Mikhail N. Grigoriev2 · Jens Strauss1 · Guido Grosse1,3 · Pier Paul Overduin1 · Aleksander Kholodov4 · Frank Guenther1 · Hans‑Wolfgang Hubberten1 Received: 22 August 2017 / Accepted: 18 May 2018 © Springer-Verlag GmbH Germany, part of Springer Nature 2018
Abstract Lagoon development in ice-rich permafrost environments such as the Alaskan Beaufort Sea coastline and the Yedoma coastlines of northern Siberia represents a key mechanism of marine inundation of permafrost along the Arctic coastal plains. Here we show lithological, geochronological, and geochemical data from a core drilled in 1999 in Ivashkina Lagoon on the Bykovsky Peninsula in northeastern Siberia. This study extends previous studies of the Ivashkina Lagoon, and provides a first dated geochronological context for sedimentation and lithological characteristics. In addition, we report ground temperature measurements from different borehole sites in and around the lagoon to support our analysis of the thermokarst lagoon environment. Furthermore, a change detection study was carried out using historical aerial photography and modern satellite imagery for the 1982–2016 period. Several stages of landscape dynamics were reconstructed, starting with an initial Yedoma Ice Complex that covered the area during the late Pleistocene and which was locally thawed by thermokarst lake development during the Late Glacial with subsequent lacustrine sedimentation. A final stage completed the landscape dynamics during the last few hundreds of years. This stage was characterized by lake drainage and lagoon development, including strong reworking of surface sediments. By extrapolating the organic carbon data from Ivashkina Lagoon to the lagoons of the Bykovsky Peninsula, we estimate that lagoons contain 1.68 ± 0.04 Mt of organic carbon in their upper 6 m. Keywords Permafrost region · Coastal dynamics · Paleoenvironment · Cryolithology · Geochronology · Hydrochemistry
Introduction Thermokarst lagoons form when thermokarst lakes or drained thermokarst lake basins are flooded by ocean water. Thermo-erosional widening (including thermo-denudation and thermo-abrasion) of the former lake outlet channels * Lutz Schirrmeister [email protected] 1
Department of Periglacial Research, Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Telegrafenberg A45, 14473 Potsdam, Germany
2
Mel’nikov Permafrost Institute, Siberian Branch of the Russian Academy of Sciences, Merzlotnaya St., 36, Yakutsk 677010, Russia
3
Institute of Earth and Environmental Science, University of Potsdam, Karl‑Liebknecht‑Str. 24‑25, 14476 Potsdam, Germany
4
Geophysical Institute, University of Alaska Fairbanks, 903 Koyukuk Drive, Fairbanks, AK 99775, USA
during the postglacial transgression and in the early Holocene transformed many thermokarst lakes along the Laptev Sea coast into lagoons [41].
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